Pan-fry the beef fillet on all sides for 10 minutes, then rest for 30 minutes on a rack so that the blood can drip down.
Chop the mushrooms, the tarragon and parsley. Peel and chop the garlic and shallots separately. Sauté the garlic and shallots in the olive oil, add the mushroom mixture and cook until the mixture has a fairly dry consistency, then season gene